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Added inflatemem from Piotr

git-svn-id: svn://svn.cc65.org/cc65/trunk@1117 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2001-11-12 21:21:38 +00:00
parent 258133cb0e
commit edb7991884

637
libsrc/zlib/inflatemem.s Normal file
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;
; Piotr Fusik, 11.11.2001
;
; void* inflatemem (void* dest, void* src);
;
.export _inflatemem
.import popax
.importzp sreg, ptr1, ptr2, ptr3, ptr4, tmp1, tmp2, tmp3, tmp4
; --------------------------------------------------------------------------
;
; Constants
;
; Maximum length of a Huffman code
MAX_BITS = 15
; Index in bitsCount, bitsPointer_l and bitsPointer_h for literal tree
LITERAL_TREE = 0
; Index in bitsCount, bitsPointer_l and bitsPointer_h for distance tree
DISTANCE_TREE = MAX_BITS
; Size of each of bitsCount, bitsPointer_l and bitsPointer_h
TREES_SIZE = 2*MAX_BITS+1
; --------------------------------------------------------------------------
;
; Page zero
;
; Pointer to compressed data
inputPointer = ptr1 ; 2 bytes
; Pointer to uncompressed data
outputPointer = ptr2 ; 2 bytes
; Buffer for getBit
getBitHold = tmp1 ; 1 byte
; Local variables. Variables from different routines use same memory.
cnt = tmp2 ; 1 byte
tmp = sreg ; 1 byte
ptr = sreg ; 2 bytes
len = ptr3 ; 2 bytes
nl = tmp3 ; 1 byte
nd = tmp4 ; 1 byte
src = ptr4 ; 2 bytes
dest = ptr4 ; 2 bytes
; --------------------------------------------------------------------------
;
; Code
;
_inflatemem:
; Get inputPointer and outputPointer from stack
jsr popax
sta inputPointer
stx inputPointer+1
jsr popax
sta outputPointer
stx outputPointer+1
ldy #1
sty getBitHold
; Get a bit of EOF and two bits of block type
inflatemem_1:
ldx #3
lda #0
jsr getBits
lsr a
tax
; X contains block type, C contains EOF flag
; Save EOF flag
php
; Go to the routine decompressing this block
jsr callExtr
plp
bcc inflatemem_1
lda outputPointer
ldx outputPointer+1
rts
; --------------------------------------------------------------------------
; Go to the routine decompressing block type X
callExtr:
lda extr_h,x
pha
lda extr_l,x
pha
rts
; --------------------------------------------------------------------------
; Decompress 'stored' data block
inflateCopyBlock:
; Ignore bits until byte boundary
ldy #1
sty getBitHold
; Get 16-bit length
ldx #inputPointer
lda (0,x)
sta len
lda (inputPointer),y
sta len+1
; Skip length and one's compliment length
lda #4
clc
adc inputPointer
sta inputPointer
bcc moveBlock
inc inputPointer+1
; fall into moveBlock
; --------------------------------------------------------------------------
; Copy block of length len from (0,x) to output
moveBlock:
ldy len
beq moveBlock_1
ldy #0
inc len+1
moveBlock_1:
lda (0,x)
sta (outputPointer),y
inc 0,x
bne moveBlock_2
inc 1,x
moveBlock_2:
inc outputPointer
bne moveBlock_3
inc outputPointer+1
moveBlock_3:
dec len
bne moveBlock_1
dec len+1
bne moveBlock_1
rts
; --------------------------------------------------------------------------
; Decompress Huffman-coded data block with default Huffman trees:
; literalCodeLength: 144 times 8, 112 times 9
; endCodeLength: 24 times 7, 6 times 8
; distanceCodeLength: 30 times 5, 2 times 8
; (2 last codes from literal tree are not used)
inflateFixedBlock:
ldx #159
stx distanceCodeLength+32
lda #8
inflateFixedBlock_1:
sta literalCodeLength-1,x
sta literalCodeLength+159-1,x
dex
bne inflateFixedBlock_1
ldx #112
lda #9
inflateFixedBlock_2:
sta literalCodeLength+144-1,x
dex
bne inflateFixedBlock_2
ldx #24
lda #7
inflateFixedBlock_3:
sta endCodeLength-1,x
dex
bne inflateFixedBlock_3
ldx #30
lda #5+DISTANCE_TREE
inflateFixedBlock_4:
sta distanceCodeLength-1,x
dex
bne inflateFixedBlock_4
jmp inflateCodes
; --------------------------------------------------------------------------
; Decompress Huffman-coded data block, reading Huffman trees first
inflateDynamicBlock:
; numberOfLiteralCodes = getBits(5) + 257;
ldx #5
lda #<(lengthCodeLength-1)
jsr getBits
sta nl
; numberOfDistanceCodes = getBits(5) + 1;
ldx #5
lda #1
jsr getBits
sta nd
clc
adc nl
sta nl
; numberOfTemporaryCodes = getBits(4) + 4;
lda #4
tax
jsr getBits
sta cnt
; Clear lengths of temporary codes (there're 19 temp codes max),
; clear literalCodeLength-1 (it may be used by temporary code 16)
; and leave #0 in Y
ldy #20
lda #0
inflateDynamicBlock_1:
sta literalCodeLength-2,y
dey
bne inflateDynamicBlock_1
; Get lengths of temporary codes in order stored in bll
inflateDynamicBlock_2:
ldx #3
lda #0
jsr getBits ; does not change Y
ldx bll,y
sta literalCodeLength,x
iny
cpy cnt
bcc inflateDynamicBlock_2
ror literalCodeLength+19 ; C flag is set, so it will set b7
; Build tree for temporary codes
jsr buildHuffmanTree
; Use temporary codes to get lengths for literal and distance codes
; dest is target-1, so we can access last written byte by (dest,0)
lda #<(literalCodeLength-1)
sta dest
lda #>(literalCodeLength-1)
sta dest+1
inflateDynamicBlock_3:
jsr fetchLiteralCode
; Temporary code 0..15: put this length
ldy #1
cmp #16
bcc inflateDynamicBlock_6
bne inflateDynamicBlock_4
; Temporary code 16: repeat last length 3..6 times
ldx #2
lda #3
jsr getBits
tay
lda (dest,x) ; X == 0
bpl inflateDynamicBlock_6 ; branch always
inflateDynamicBlock_4:
lsr a
; Temporary code 17: put zero length 3..10 times
lda #3
tax
bcs inflateDynamicBlock_5
; Temporary code 18: put zero length 11..138 times
ldx #7
lda #11
inflateDynamicBlock_5:
jsr getBits
tay
lda #0
; Write A length Y times
inflateDynamicBlock_6:
sty cnt
inflateDynamicBlock_7:
sta (dest),y
dey
bne inflateDynamicBlock_7
lda cnt
clc
adc dest
sta dest
bcc inflateDynamicBlock_8
inc dest+1
inflateDynamicBlock_8:
cmp nl
bne inflateDynamicBlock_3
ldy dest+1
sbc #<endCodeLength ; C flag is set
bcs inflateDynamicBlock_11
dey
inflateDynamicBlock_11:
cpy #>endCodeLength
bcc inflateDynamicBlock_3
; Mark end of distance lengths
ldx nd
tay
ror distanceCodeLength,x ; C flag is set, so it will set b7
; Move distance lengths to distanceCodeLength table
inflateDynamicBlock_9:
dex
lda endCodeLength,y
; Mark existing codes (of non-zero length) as distance tree codes
beq inflateDynamicBlock_10
pha
lda #0
sta endCodeLength,y
pla
clc
adc #DISTANCE_TREE
sta distanceCodeLength,x
inflateDynamicBlock_10:
dey
txa
bne inflateDynamicBlock_9
; fall into inflateCodes
; --------------------------------------------------------------------------
; Decompress data block basing on given Huffman trees
inflateCodes:
jsr buildHuffmanTree
inflateCodes_1:
jsr fetchLiteralCode
bcc inflateCodes_2
; Literal code
ldy #0
sta (outputPointer),y
inc outputPointer
bne inflateCodes_1
inc outputPointer+1
bcs inflateCodes_1 ; branch always
; End of block
inflateCodes_ret:
rts
inflateCodes_2:
beq inflateCodes_ret
; Repeat block
jsr getValue
sta len
tya
jsr getBits
sta len+1
ldx #DISTANCE_TREE
jsr fetchCode
jsr getValue
sta src
tya
jsr getBits
sta src+1
lda outputPointer
sec
sbc src
sta src
lda outputPointer+1
sbc src+1
sta src+1
ldx #src
jsr moveBlock
beq inflateCodes_1 ; branch always
; --------------------------------------------------------------------------
; Build Huffman trees basing on code lengths.
; Lengths (in bits) are stored in literalCodeLength.
; A byte with highest bit set marks end of length table.
buildHuffmanTree:
lda #<literalCodeLength
sta buildHuffmanTree_3+1
sta buildHuffmanTree_9+1
lda #>literalCodeLength
sta buildHuffmanTree_3+2
sta buildHuffmanTree_9+2
; Clear counts
ldx #TREES_SIZE-1
lda #0
buildHuffmanTree_1:
sta bitsCount,x
dex
bpl buildHuffmanTree_1
bmi buildHuffmanTree_3 ; branch always
; Count number of codes of each length
buildHuffmanTree_2:
inc bitsCount,x
inc buildHuffmanTree_3+1
bne buildHuffmanTree_3
inc buildHuffmanTree_3+2
buildHuffmanTree_3:
ldx $ffff ; patched at runtime
bpl buildHuffmanTree_2
; Calculate pointer for each length
tax ; ldx #0
stx bitsCount
lda #<sortedCodes
ldy #>sortedCodes
buildHuffmanTree_4:
sta bitsPointer_l,x
tya
sta bitsPointer_h,x
lda bitsCount,x
asl a
bcc buildHuffmanTree_5
iny
clc
buildHuffmanTree_5:
adc bitsPointer_l,x
bcc buildHuffmanTree_6
iny
buildHuffmanTree_6:
inx
cpx #TREES_SIZE
bcc buildHuffmanTree_4
bcs buildHuffmanTree_9 ; branch always
; Put codes into their place in sorted table
buildHuffmanTree_7:
beq buildHuffmanTree_8
lda bitsPointer_l,x
sta ptr
clc
adc #2
sta bitsPointer_l,x
lda bitsPointer_h,x
sta ptr+1
adc #0
sta bitsPointer_h,x
lda buildHuffmanTree_9+1
sbc #<(endCodeLength-1) ; C flag is zero
ldy #1
sta (ptr),y
lda buildHuffmanTree_9+2
sbc #>(endCodeLength-1)
.ifpc02
sta (ptr)
.else
dey
sta (ptr),y
.endif
buildHuffmanTree_8:
inc buildHuffmanTree_9+1
bne buildHuffmanTree_9
inc buildHuffmanTree_9+2
buildHuffmanTree_9:
ldx $ffff ; patched at runtime
bpl buildHuffmanTree_7
rts
; --------------------------------------------------------------------------
; Read code basing on literal tree
fetchLiteralCode:
ldx #LITERAL_TREE
; fall into fetchCode
; --------------------------------------------------------------------------
; Read code from input stream basing on tree given in X.
; Return code in A, C is set if non-literal code.
fetchCode:
lda #0
fetchCode_1:
jsr getBit
rol a
cmp bitsCount+1,x
bcc fetchCode_2
sbc bitsCount+1,x
inx
bcs fetchCode_1 ; branch always
fetchCode_2:
ldy bitsPointer_l,x
sty ptr
ldy bitsPointer_h,x
asl a
bcc fetchCode_3
iny
fetchCode_3:
sty ptr+1
tay
lda (ptr),y
asl a
iny
lda (ptr),y
rts
; --------------------------------------------------------------------------
; Read low byte of value (length or distance), basing on code A
getValue:
tay
ldx lengthExtraBits-1,y
lda lengthCode_l-1,y
pha
lda lengthCode_h-1,y
tay
pla
; fall into getBits
; --------------------------------------------------------------------------
; Read X-bit number from input stream and adds it to A.
; In case of carry, Y is incremented.
; If X > 8, only 8 bits are read.
; On return X holds number of unread bits: X = (X > 8 ? X - 8 : 0);
getBits:
cpx #0
beq getBits_ret
pha
lda #1
sta tmp
pla
getBits_1:
jsr getBit
bcc getBits_2
clc
adc tmp
bcc getBits_2
iny
getBits_2:
dex
beq getBits_ret
asl tmp
bcc getBits_1
getBits_ret:
rts
; --------------------------------------------------------------------------
; Read single bit from input stream, return it in C flag
getBit:
lsr getBitHold
bne getBit_ret
pha
.ifpc02
lda (inputPointer)
.else
tya
pha
ldy #0
lda (inputPointer),y
.endif
inc inputPointer
bne getBit_1
inc inputPointer+1
getBit_1:
ror a ; C flag set
sta getBitHold
.ifpc02
.else
pla
tay
.endif
pla
getBit_ret:
rts
; --------------------------------------------------------------------------
; Addresses of functions extracting different blocks
extr_l:
.byte <(inflateCopyBlock-1)
.byte <(inflateFixedBlock-1)
.byte <(inflateDynamicBlock-1)
extr_h:
.byte >(inflateCopyBlock-1)
.byte >(inflateFixedBlock-1)
.byte >(inflateDynamicBlock-1)
; --------------------------------------------------------------------------
; Order, in which lengths of temporary codes are stored
bll:
.byte 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15
; --------------------------------------------------------------------------
; Tables for length and distance codes
; Value is Code + getBits(ExtraBits)
; Base values
lengthCode_l:
.byte <3,<4,<5,<6,<7,<8,<9,<10
.byte <11,<13,<15,<17,<19,<23,<27,<31
.byte <35,<43,<51,<59,<67,<83,<99,<115
.byte <131,<163,<195,<227,<258
distanceCode_l:
.byte <1,<2,<3,<4,<5,<7,<9,<13
.byte <17,<25,<33,<49,<65,<97,<129,<193
.byte <257,<385,<513,<769,<1025,<1537,<2049,<3073
.byte <4097,<6145,<8193,<12289,<16385,<24577
lengthCode_h:
.byte >3,>4,>5,>6,>7,>8,>9,>10
.byte >11,>13,>15,>17,>19,>23,>27,>31
.byte >35,>43,>51,>59,>67,>83,>99,>115
.byte >131,>163,>195,>227,>258
distanceCode_h:
.byte >1,>2,>3,>4,>5,>7,>9,>13
.byte >17,>25,>33,>49,>65,>97,>129,>193
.byte >257,>385,>513,>769,>1025,>1537,>2049,>3073
.byte >4097,>6145,>8193,>12289,>16385,>24577
; Number of extra bits to read
lengthExtraBits:
.byte 0,0,0,0,0,0,0,0
.byte 1,1,1,1,2,2,2,2
.byte 3,3,3,3,4,4,4,4
.byte 5,5,5,5,0
distanceExtraBits:
.byte 0,0,0,0,1,1,2,2
.byte 3,3,4,4,5,5,6,6
.byte 7,7,8,8,9,9,10,10
.byte 11,11,12,12,13,13
; --------------------------------------------------------------------------
;
; Uninitialised data
;
.bss
; --------------------------------------------------------------------------
; Data for building literal tree
.res 1
; Length of literal codes
literalCodeLength:
.res 256
; Length of 'end' code
endCodeLength:
.res 1
; Length of 'length' codes
lengthCodeLength:
.res 29
; --------------------------------------------------------------------------
; Data for building distance tree
distanceCodeLength:
.res 30
; For two unused codes in fixed trees and an end flag
.res 3
; --------------------------------------------------------------------------
; Huffman tree structure
; Number of codes of each length
bitsCount:
.res TREES_SIZE
; Pointer to sorted codes of each length
bitsPointer_l:
.res TREES_SIZE
bitsPointer_h:
.res TREES_SIZE
; Sorted codes
sortedCodes:
.res 2*(256+1+29+30+2)